1. Field of the Invention
The invention relates to sandal structures and methods of making sandals.
2. Description of the Prior Art
Sandals are widely used by men, woman and children throughout the world. There are a wide variety of sandal structures which are suitable for various manufacturing techniques or for being handmade. Sandals are also widely used in the United States, especially by women and children. Children's sandals need to be especially durable in order to withstand the rough treatment which they receive from most children.
The shoe manufacturing industry throughout the United States, Europe and the Far East, is highly competitive. The sandal segment of the shoe industry is no different in this respect than the rest of the shoe industry. The shoe manufacturing industry in the United States has experienced a marked decline in recent years, due to high labor costs and high costs of manufacturing equipment and machinery. Because labor costs are much lower, less expensive shoe manufacturing machinery is required for overseas shoe manufacturing operations. Consequently, most shoes now sold in the United States are manufactured overseas.
Present sandals have structures which necessitate use of a relatively large amount of hand labor or use of very complex and extensive automatic manufacturing equipment for making such sandals. One common sandal structure includes a composition rubber sole to which a leather insole is adhesively bonded. The leather insole includes a plurality of elongated rectangular slots extending through the insole along the major edges of the insole. Toe straps and ankle straps having enlarged ends for the upper portion of the sandal. The enlarged ends of the toe straps and ankle straps are inserted through the elongated slots and are bent inwardly against the lower surface of the insole before the resulting assembly is adhesively bonded to the upper surface of the composition rubber sole. Ordinary buckles are utilized to fasten opposing toe straps and ankle straps. The above described sandal structure is widely used, but has a number of shortcomings. One of the most serious shortcomings of the foregoing sandal structure is that the enlarged ends of the respective straps are often loosened or pulled out of the slots when the sandal is subjected to rough treatment, as by active children. If even one enlarged end of a sandal is pulled loose in this manner the sandal and its mate are, for all practical purposes useless, since repair of the sandal structure is impractical. Although adhesive bonding between the insole and sole is economical and relatively durable, such bonding tends to gradually weaken because ordinary wear, especially in children's sandals produces great stresses at the edges of the bonding, thereby separating the bond at the edges of the sandals. The ordinary wear stresses then cause the separation to gradually spread inward, until the tabs become loosened. There is clearly an unmet need for an improved, low cost sandal having straps which do not become loosened by rough treatment.
Accordingly, it is an object of the invention to provide an improved sandal having straps which do not become loosened as a result of rough treatment received from wearers, especially children.
Another shortcoming of the above described sandal structure is that the described tabs extend between the insole lower surface and the upper surface of the composition rubber sole, thereby producing bumps which are often uncomfortable to the wearer.
Accordingly, another object of the invention is to provide an improved sandal which does not have bumps along the edges of its insole.
The above described sandal structure requires use of expensive machinery in order to cut the leather strap sections. The sandal structure requires individual strap sections, which are punched from a piece of leather by utilizing powerful, expensive punches. The necessity of providing a number of individual straps increases the cost of such equipment. The necessity of punching the elongated slots in the insole necessitates use of more expensive machinery and labor than would be necessary if the slots were not required. Expensive, complicated machinery is also required to accomplish the task of inserting the enlarged ends of the straps into the slots of the insole prior to adhesively bonding the insole and strap assembly to the composition rubber sole. Thus, there is an unmet need for a sandal having a structure capable of being manufactured with less complex and expensive machinery, less labor, and fewer complex manufacturing steps than the above described sandal.
Accordingly, another object of the invention is to provide an improved sandal having a structure which is more easily and less expensively manufactured than sandal structures of the prior art.
Still another object of the invention is to provide an improved method of manufacturing sandals.
Yet another object of the invention is to provide a sandal structure and method of making which overcomes the above described shortcomings of the prior art.